The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 30, 1993
Filed:
Dec. 11, 1990
Malcolm S McClure, Indianapolis, IN (US);
Phong B Chau, Indianapolis, IN (US);
Span, Inc., Indianapolis, IN (US);
Abstract
A battery charger has battery terminals connected to a conventional wall outlet through a switching power supply to provide a direct conductive non-isolated path from the supply for direct transformer-less supply of charging current to a battery. Pulse width modulated signals are applied to a MOSFET of the power supply from an output port of a microprocessor which is operates a ramp generator and responds to a comparator circuit coupled to a battery voltage sense circuit and the ramp generator. The microprocessor is programmed to accurately control generation of the pulse width modulated signals, to shut off current when a true voltage peak is reached at a full charge condition, to avoid response to false peaks, to cut off current for short time intervals during voltage measurements, to perform an exponential averaging function and to shut down at excessive battery temperatures or time rates of change of battery temperature.